Passive chipless RFID-based crack sensor for metal components

Abstract:

In order to realize the demand for low-cost and long-term detection of large-scale building groups and to expand the identification range of the sensor, this paper proposed a metal crack sensor based on passive chipless radio frequency identification (RFID) technology. Based on the influencing factors such as cross-polarization and operating bandwidth and a large amount of simulation data on the HFSS platform in the early stage, the paper designed a sensor model with excellent detection performance. Horizontal, vertical, and diagonal cracks were constructed, and electromagnetic excitation of the plane wave was used to test the influence of different crack shapes on the sensing and detection. The position of various types of cracks was changed, and changes in the electric field of the resonant cavity, current, and response amplitude were analyzed to determine the optimal identification range of the sensor. The results show that the average amplitude deviation of the sensor’s response to structural damage detection is 5 dB in the ultra-high frequency band. The change of crack position will affect the surface current distribution, which will change the response amplitude, while the structural damage response is detuned compared with the crack-free response, and the change of crack position does not affect the detectability of cracks. The sensor is capable of detecting cracks in different directions at any position on the surface of an object over a full range, improving the identification range and enabling real-time monitoring of cracks with small positional variations at a high resolution.